Wendy,Thanks for confirming my suspicions aabout the importance of Packagesand Shares. Why is this such a secret? In Northampton Arrays andShares is one of 5 Core units for grade 4. Packages and Shares is notbut looks like it should be. Any more information on choosing unitswould be appreciated. i am currently helping Holyoke, MA choose unitsto include in its curriculum and and this kind of info is so useful. Joan